Acquisitions - Additional Information (Detail) - USD ($)	1 Months Ended		3 Months Ended		9 Months Ended
	Mar. 31, 2019	Nov. 30, 2018	Mar. 31, 2019	Sep. 30, 2018	Mar. 31, 2019	Jun. 30, 2018
Business Acquisition [Line Items]
Goodwill	$ 319,935,000		$ 319,935,000		$ 319,935,000	$ 270,678,000
II-VI Photonics Segment
Business Acquisition [Line Items]
Goodwill	135,663,000		135,663,000		135,663,000	$ 109,670,000
CoAdna Holdings, Inc.
Business Acquisition [Line Items]
Net cash paid at acquisition				$ 85,000,000
Acquisition, inclusive of cash acquired				42,200,000
Goodwill				24,844,000
Business acquisition, transaction costs	1,900,000		1,900,000		1,900,000
Fair value of accounts receivable acquired				5,700,000
Fair value of accounts receivable gross contractual amount				5,700,000
Goodwill deductible for income tax purposes				0
Business acquisition, revenue of acquired entity			2,300,000		12,400,000
Business acquisition, Inventory acquired				6,189,000
Intangible assets				16,072,000
CoAdna Holdings, Inc. | II-VI Photonics Segment
Business Acquisition [Line Items]
Goodwill				$ 24,800,000
Product Line
Business Acquisition [Line Items]
Net cash paid at acquisition		$ 10,000,000
Goodwill		1,200,000
Business acquisition, Inventory acquired		200,000
Business acquisition, equipment acquired		2,300,000
Product Line | Technology-Based Intangible Assets
Business Acquisition [Line Items]
Intangible assets		$ 6,300,000
Redstone Aerospace Corporation
Business Acquisition [Line Items]
Net cash paid at acquisition	27,959,000
Goodwill	19,700,000		19,700,000		19,700,000
Intangible assets	9,100,000		9,100,000		9,100,000
Redstone Aerospace Corporation | Upon Achievement of Financial Objectives | Maximum
Business Acquisition [Line Items]
Business acquisitions, contingent consideration	2,000,000		2,000,000		2,000,000
Redstone Aerospace Corporation | Technology-Based Intangible Assets
Business Acquisition [Line Items]
Intangible assets	$ 9,100,000		$ 9,100,000		$ 9,100,000